Polio campaign for Yemeni children

A Yemeni child receives a polio vaccination during a polio immunization campaign at a health center in Sanaa, on December 16, 2013. A three-day anti-polio immunization campaign to vaccinate more than four million children under five years old against polio began. The World Health Organisation and UNICEF have launched a polio vaccination campaign for 23 million children in the Middle East after 17 cases were discovered in Syria, they announced December 9. (AFP/Getty Images)